When you create a paragraph in a topic you can add text, character styles, images, variables, hyperlinks and embedded topics.
You do not have to create rules for inline content. You only need to create a rule when you want to place restrictions on a specific type of inline content. For example, you can create a rule to limit the number of character styles that can be used in the paragraph, but leave all other forms of inline content without any restrictions.
No restrictions on child content
In structured authoring rules determine any restrictions that are placed on content used in a paragraph. By default, when you create a paragraph level rule all inline content (the content controlled by the child rules) is allowed without any restrictions. This means that the author can add any character styles, images, hyperlinks, variables, or embedded topics to the content. As long as the paragraph rule meets validation requirements for the paragraph style and occurrence and location, the extra content will validate because no child rules have been created to introduce restrictions.
Using rules to enforce restrictions
When you create a rule you begin the process of introducing restrictions on how content is used. If you want to put restrictions on content you create a rule that determines the objects (or templates) that can be used, and the number of times or order within the paragraph that the content can be used. Once you create an inline rule the content must meet the requirements so the paragraph content can validate.
Using rules to prohibit use of child content
Inline rules can be used to prohibit use of a specific type of content in a paragraph. This is achieved by creating an inline rule and setting both occurrence levels to zero. When both levels are set at zero the Allowed Objects list is disabled. If any instances of that type of content are added to the paragraph then the paragraph will not validate. For example, if a rule is created to prohibit use of images then no images should be used in the paragraph content.